Vector Magnetic Field Sensing at Tiny Angles Through a Nanofluid Functionalized Ultrathin Taper Interferometer

Abstract

Abstract Aiming at the requirement of high precision and long life in tasks of mechanical and navigation industries, a highly sensitive and compact, magnetorheological fluid film-suspended nonadiabatic biconical tapered optical fiber interferometer-based vector magnetometer has been proposed and demonstrated in the manuscript. The reported magnetometer keeps the ability to detect the strength of the magnetic field and its direction in the 3D plane concurrently. Magnetically regulated effective index amendment is used to stimulate the higher order modes propagating in the cladding region of the ultrathin biconical fiber interferometer. Hence, the detection principle of the sensor depends on the changes in the effective indices of higher-order excited modes with respect to the applied magnetic field. The proposed magnetometer detects slight angular variations of -2° to +2° in the magnetic field over a broad range from 0 mT to 567 mT by using the azimuth-dependent anisotropic distribution of nanoparticles in the vicinity of the fiber-optic sensor arm. The reported sensor offers to its angular sensitivities of ~ ∓14.68 pm/mT, and ~ ∓11.79 pm/mT at minor inclinations of ∓1° and ∓2° whereas having its maximum sensitivity of ~ 16.48 pm/mT at 0°.